The present invention relates to optical modules and methods for manufacturing the optical modules and, more particularly, to an optical module in which an optical part such as a lens is fixed to a substrate made of silicon or the like by use of an adhesive, and a method for manufacturing the optical module.
The market scale of products relevant to an optical communication field is growing with advanced information-oriented society. Under this circumstance, a thorough low cost of an optical module is required. Examples of means for achieving the low cost of an optical module include a method disclosed by for example Japanese Patent Laid-open No. 2000-121883, i.e., Prior Art 1. In this method, a substrate made of silicon is used to form a V-shaped groove with a high degree of precision in the surface of the substrate by anisotropic etching, and then, a lens is put into the V-shaped groove by passive alignment. This eliminate the need for carrying out the so-called active alignment in which a semiconductor laser is made to emit light, the position of the lens is adjusted in such a manner as to achieve a greatest optical output, and thereafter, the lens is fixed at the adjusted position. Thus, it is possible to remarkably shorten a lens putting time so as to reduce the cost of the optical module.
On the other hand, Japanese Patent Application Laid-open No. 2001-94191, i.e., Prior Art 2 discloses that an optical part such as a spherical lens is adhesively fixed to a silicon substrate at a V-shaped groove formed therein by anisotropic etching by use of a resin having a glass transition temperature lower than a lowest temperature within the range of operating temperatures of an optical semiconductor element. Furthermore, Prior Art 2 discloses that the optical part is instantaneously fixed onto the substrate by use of an ultraviolet curable type resin such as an epoxy resin.